The invention relates to solder preforms for use in joining one object to another, and more specifically to an integrated preform array (preform) used for joining electronic components to connectors, circuit board terminals and other elements.
U.S. Pat. No. 5,242,097 teaches that a solder preform once applied to terminals or pin components to be soldered, will not become easily dislodged when the assembly is handled prior to the soldering operation. More specifically, U.S. Pat. No. 5,242,097 provides an integrated solder preform array in which individual bridging strands of solder cojoin solder islands positively, and reliably separate in the midregion of the strands so that the separated halves retract to adjacent solder islands in a positive and uniform fashion.
The preforms of the type taught by U.S. Pat. No. 5,242,097 typically are made of an alloy which, when exposed for any significant period of time to the atmosphere, tend to form surface oxides. The formation of these surface oxides sometimes creates problems by impeding the proper wetting of the solder, in-turn preventing the strands connecting the integrated preform array islands from efficiently separating and retracting to the preform islands. When this occurs, an electrical short can be caused due to the unwanted electrical contact between adjacent individual pins.
It can therefore be seen that there is a need for an improved integrated solder preform array which provides for ease of wetting during the soldering operation, and for a clean break of the strands connecting each solder preform island. Such a preform would eliminate the problem of unwanted shorting of circuit boards or other electrical components being soldered. It is, therefore, an object of the present invention to overcome the problems noted above.